1. Technical Field
The present invention relates to a technology of driving an energy converter by a PWM signal.
2. Related Art
As disclosed in JP-A-2006-109675, electrical machines such as motors driven by three-phase AC are widely used as apparatuses that convert electrical energy into mechanical energy and vice versa. In the motor driven by three-phase AC, magnetic coils of the motor are star-connected or delta-connected.
However, when a polyphase motor is PWM-driven, improvement in efficiency and output of the entire polyphase motor has not been studied sufficiently under present circumstances.